New research to be presented on Thursday 6th October at the EPSC-DPS Joint Meeting in Nantes rewrites our theories of how Uranus became so tilted and also solves fresh mysteries about the position and orbits of its moons.

Retrograde Motion -- Retrograde motion is the orbital motion of a body in a direction opposite that which is normal to spatial bodies within a given system. 'Retrograde' derives from the Latin words retro, backwards, and gradus, step.
In the Solar system, mostly everything rotates in the same sense: all major planets orbit the Sun counterclockwise as seen from the pole star (Polaris). Most planets spin in the same sense, including Earth. The same happens with the orbital motions of the...

Planet Triton -- Triton is the planet Neptune's largest moon, discovered by William Lassell in 1846 just 17 days after the planet itself was discovered.
It is named after Triton, from Greek mythology.
Triton is unique among all large moons in the solar system for its retrograde orbit around the planet (i.e., it orbits in a direction opposite to the planet's rotation). Jupiter's moons Ananke, Carme, Pasiphae and Sinope and Saturn's moon Phoebe also orbit retrograde, but all of them...

A pivoted catch designed to fall into a notch on a ratchet wheel so as to allow movement in only one direction (e.g. on a windlass or in a clock mechanism), or alternatively to move the wheel in one direction.